Distribution features of dinitrotoluene in Ipomoea aquatic-soil-leachate system for agricultural use of municipal sludge

Ipomoea aquatic was potted in paddy soil applied with municipal sludge and chemical fertilizer, and 2,4-dinitrotoluene and 2,6-dinitrotoluene in plant, soil and leachate were determined by GC/MS to investgate distribution features of dinitrotoluene in Ipomoea aquatic-soil-leachate system. Results show that the concentrations of 2,4-dinitrotoluene and 2,6-dinitrotoluene range from 0.035 mg/kg to 0.307 mg/kg and from 0.007 mg/kg to 0.392 mg/kg in Ipomoea aquatic, respectively, and from 0.015 mg/kg to 0.146 mg/kg and from below detection limit to 0.285 mg/kg in soil respectively. The concentrations of 2,4-dinitrotoluene and 2,6-dinitrotoluene in leachate were less than 0.10 mg/L and below detection limit respectively. Both municipal sludge and chemical fertilizer resulted in accumulation of 2,6-dinitrotoluene in Ipomoea aquatic and soil, and the accumulation of 2,4-dinitrotoluene in leachate as well as 2,4-dinitrotoluene in chemical fertilizer were much more bioavailable than 2,6-dinitrotoluene. Biolavailabilities of 2,4-dinitrotoluene and 2,6-dinitrotoluene in municipal sludge were both affected by applying chemical fertilizer to promote the former while inhibit the latter, which increased the uptake of 2,4-dinitrotoluene by plant and accumulation of 2,6-dinitrotoluene in soil.